Color filter and method of making the same

ABSTRACT

A template ( 12 ) having a plurality of protrusions ( 13 ) in a predetermined arrangement is fabricated to facilitate the formation of ink filling concavities for forming a color pattern layer. An ink filling layer precursor ( 11 ) is attached to the template ( 12 ) and, after the ink filling layer precursor ( 11 ) has solidified to form an ink filling layer ( 14 ), the ink filling layer ( 14 ) having a plurality of ink filling concavities ( 15 ) is transfer-formed by separating the ink filling layer ( 14 ) from the template ( 12 ). Ink of previously determined colors are filled into these ink filling concavities ( 15 ) to form a color pattern layer ( 16 ).

TECHNICAL FIELD

[0001] The present invention relates to a color filter for use in aliquid crystal display panel or the like, and a method of making thesame.

BACKGROUND ART

[0002] Methods of making a color filter for a liquid crystal displaypanel or the like include dyeing, pigment dispersion, printing, andelectrodeposition methods. Of these fabrication methods, the printingmethod has a drawback with respect to accuracy, and theelectrodeposition method has a drawback concerning patterningrestrictions, and for those reasons the dyeing method and pigmentdispersion method have been most widely used in the art.

[0003] However, the dyeing method and the pigment dispersion method eachrequire a lithography step for forming the pixel regions for each of thefirst color, second color, and third color, which is a big obstacle toimproving the efficiency of mass production. One method for formingpixels without such a lithography step for each color is an inkjetmethod of making a color filter, which is disclosed in a number ofpublications, such as Japanese Patent Application Laid-Open No. 59-75205and Japanese Patent Application Laid-Open No. 61-245106. Using an inkjetmethod to form the color pattern improves the efficiency of use ofmaterials and shortens the process, and it is also possible to controlthe formation of the color pattern and thus obtain a color filter thatis inexpensive but of a high quality.

[0004] In such a method of making a color filter using an inkjet method,one means that has been proposed to prevent ink from spreading outsideof each colored region, and thus implement highly precise coloring, isto use pixel delimiting regions that are formed previously byphotolithography on the substrate. Ink filling concavities are thusformed on the substrate by the pixel delimiting regions, to control theshape of a color pattern that is formed by filling these ink fillingconcavities with ink.

[0005] These pixel delimiting regions are often formed of an opaquematerial so that they also function as a black matrix (hereinafterabbreviated to BM).

[0006] In this case, a high level of precision is required for theformation of the pixel delimiting regions, but it is difficult toperform such highly precise processing while improving themass-productivity of the process. In addition, flatness is required whenforming a transparent electrode on the color filter, but it has beendifficult to increase the precision of this flatness in the past.

[0007] The present invention has been devised in order to solve theabove problems, and has the objective of providing a method of making aninexpensive, highly precise color filter with a reduced number of steps,as well as a color filter fabricated by that method.

DISCLOSURE OF INVENTION

[0008] A method of making a color filter in accordance with the presentinvention comprises: a first step of fabricating a template having aplurality of protrusions in a predetermined array;

[0009] a second step of transfer-forming an ink filling layer having aplurality of ink filling concavities by causing an ink filling layerprecursor to adhere to the template, solidifying the ink filling layerprecursor to form the ink filling layer, then separating the ink fillinglayer from the template; and

[0010] a third step of filling the ink filling cavities with inks ofpreviously determined colors, to form a color pattern layer.

[0011] In other words, the present invention uses a template as a moldto transfer-form an ink filling layer having ink filling concavities.Once this template has been fabricated, it can be used a number of timeslimited by the durability thereof. Therefore step can be omitted fromthe process of forming the second and subsequent color filters, thusreducing the number of steps and the cost.

[0012] Specific methods of fabricating the template are described below.

[0013] (1) A step of forming a resist layer of a predetermined patternon a substrate, then forming the protrusions on the substrate by etchingto obtain the template.

[0014] This step makes it possible to control the shape and surfaceroughness of the protrusions in a highly precise and also unrestrictedmanner, by varying the etching conditions.

[0015] A silicon wafer is preferably used as this substrate. Thetechnique of etching a silicon wafer is used as a technique in thefabrication of semiconductor devices, and enables highly preciseprocessing.

[0016] (2) A step of forming a resist layer of a predetermined patternon a base plate, then making the base plate and the resist layerconductive, and further using electrodeposition to deposit metal by anelectroplating method to form a metal layer, and finally separating themetal layer from the base plate and the resist layer to obtain thetemplate.

[0017] A metal template obtained by this step generally has superlativedurability and separability.

[0018] This ink filling layer precursor is preferably a material whichcan be hardened by the application of energy. The use of such a materialmakes it possible for the material that forms the ink filling layer toeasily fill as far as the most detailed parts of the concavities in thetemplate, so that the shape of the protrusions on the template can betransferred accurately to form the ink filling concavities.

[0019] The energy is preferably at least one of light and heat. Thismakes it possible to use a general-purpose exposure apparatus, bakingoven, or hotplate, enabling reductions in equipment costs andinstallation space.

[0020] A resin which is hardened by ultraviolet rays is an example ofsuch a material. An acrylic resin has superlative transparency as aresin which is hardened by ultraviolet rays, and it is suitable becausevarious commercially available resins and photosensitive materials canbe used therefor.

[0021] Next, the ink is preferably injected by an inkjet method in thethird step. The use of an inkjet method enables rapid application of theink and there is also no waste of such ink.

[0022] In a further aspect of the present invention, an opaque materialmay be injected into concavities between the protrusions of the templateafter the first step but before the second step, to form an opaquelayer; and

[0023] the opaque layer is integrated with the ink filling layer in thesecond step, by using the template on which is formed the opaque layer.

[0024] This opaque material may also be injected by an inkjet method.

[0025] The inner side surfaces of the concavities of the template may beformed in a tapered shape in such a manner that the surface area ofaperture portions thereof are larger than base surfaces thereof.

[0026] These concavities of the template may also be formed in a taperedshape at aperture edge portions of inner side surfaces thereof.

[0027] If the concavities are formed in a tapered shape in this manner,the inks can be guided reliably into the concavities, thus making thecolor filter particularly suitable for use in a high-resolution liquidcrystal panel. In addition, this configuration reduces any difference inthickness of the color pattern layer, thus reducing unevenness in colorcaused by factors such as differences in color tone or brightness, andthus making it possible to fabricate a color filter that provides abright image.

[0028] Another method of making a color filter in accordance with thepresent invention comprises: a first step of forming a plurality ofcolored layers;

[0029] a second step of placing a precursor of a protective film on thecolored layers; and

[0030] a third step of forming a protective film precursor layer byflattening a surface of the protective film precursor with a templatehaving a flat surface corresponding to at least an optically transparentregion (filter element) of the colored layers, then hardening theprotective film precursor layer to form a protective film. This methodmakes it possible to form the surface of the protective film to be flat.

[0031] With the present invention, at least one concavity could beprovided in a surface of the template corresponding to a region otherthan an optically transparent region of the colored layers;

[0032] the shape of the concavities of the template is transferred tothe protective film precursor layer in the third step, to formprotrusions in the protective film corresponding to the concavities; and

[0033] the protrusions act as support members (spacer) for maintaining aconstant spacing (cell gap) for injecting liquid crystal into a liquidcrystal panel (liquid crystal cell). This method makes it possible toform support members simultaneously with the protective film, and alsoeasily adjust the positions at which the support members are disposed.

[0034] In this aspect of the invention, the second step could cause theconcavities of the template to be positioned above and between thecolored layers.

[0035] This forms support members between the colored layers. Inaddition, if an opaque layer (black matrix) is formed between thecolored layers, protrusions that act as support members could bepositioned on top of this opaque layer. For example, the opaque layercould be formed as a lattice, with the support members formed atintersection points of this lattice. Since this method makes it possibleto not form support members on the colored layers, it enables animprovement in yield and also simplifies the fabrication process.

[0036] The concavities could also be formed in a circular cylindricalshape. This causes the protrusions that act as support members to have acircular cylindrical shape, making it possible to suppress disturbancesin the orientation of the liquid crystal and increase the contrast ofthe liquid crystal panel display.

[0037] It is preferable that the protective film precursor is a materialwhich can be hardened by the application of energy. This energy may beat least one of light and heat, for example. The protective filmprecursor could be a resin which is hardened by ultraviolet rays.

[0038] With this aspect of the invention, a transparent electrode filmcould be previously formed on the template; and

[0039] after the transparent electrode film is placed in contact withthe protective film precursor, the protective film precursor layer isformed by the template, and the protective film precursor is hardened toform a protective film in the third step, the template is separated fromthe protective film precursor layer, leaving the transparent electroderemaining on the protective film precursor layer. This makes it possibleto form the transparent electrode film in a simple manner.

[0040] A separation layer could also be formed between the template andthe transparent electrode film, to promote the separation of the twocomponents. This facilitates the removal of the template from theprotective film precursor, leaving the transparent electrode film.

[0041] A color filter in accordance with the present invention comprisesan ink filling layer having a plurality of ink filling concavities; anda color pattern layer formed in the ink filling cavities; and

[0042] wherein the ink filling layer is formed by causing a templatehaving a plurality of protrusions in a predetermined array to adhere toan ink filling layer precursor, then solidifying the ink filling layerprecursor.

[0043] Another color filter in accordance with the present inventioncomprises a plurality of colored layers; and a protective film formed onthe colored layers; and

[0044] wherein the protective film is formed by flattening a surface ofthe protective film precursor with a template having a flat surfacecorresponding to at least an optically transparent region of the coloredlayers, then hardening the protective film precursor layer.

BRIEF DESCRIPTION OF DRAWINGS

[0045]FIGS. 1A to 1F illustrate the process of making a template of afirst embodiment of the present invention;

[0046]FIGS. 2A to 2E illustrate the process of making a color filter ofthe present embodiment of the invention;

[0047]FIG. 3 illustrates the process of making a color pattern layer ofthe present embodiment of the invention;

[0048]FIGS. 4A to 4C illustrate the process of fabricating a template ofa second embodiment of the present invention;

[0049]FIGS. 5A to 5C illustrate the rest of the process of fabricatingthe template of the second embodiment of the present invention;

[0050]FIG. 6 is a plan view of a color filter made in accordance with athird embodiment of the present invention;

[0051]FIGS. 7A to 7E illustrate the process of fabricating a template ofa third embodiment;

[0052]FIGS. 8A to 8D illustrate the process of fabricating a colorfilter of the present invention;

[0053]FIG. 9 illustrates in detail the process of filling an opaquematerial;

[0054]FIG. 10 illustrates in detail the process of filling colored inks;

[0055]FIGS. 11A to 11C illustrate the process of fabricating a templateof a fourth embodiment;

[0056]FIGS. 12A to 12C illustrate the rest of the process of fabricatingthe template of the fourth embodiment;

[0057]FIGS. 13A and 13B illustrate a state in which opaque ink fills anordinary template;

[0058]FIGS. 14A and 14B illustrate a state in which opaque ink fills atemplate of a fifth embodiment;

[0059]FIGS. 15A and 15B illustrate a state in which opaque ink fills amodification of the template of the fifth embodiment;

[0060]FIGS. 16A to 16C illustrate the process of fabricating a colorfilter of a sixth embodiment;

[0061]FIGS. 17A to 17C further illustrate the process of fabricating thecolor filter of the sixth embodiment;

[0062]FIGS. 18A to 18C further illustrate the process of fabricating thecolor filter of the sixth embodiment;

[0063]FIGS. 19A to 19C illustrate the rest of the process of fabricatingthe color filter of the sixth embodiment;

[0064]FIGS. 20A to 20C illustrate the process of fabricating a colorfilter of a seventh embodiment;

[0065]FIGS. 21A to 21C illustrate the rest of the process of fabricatingthe color filter of the seventh embodiment;

[0066]FIGS. 22A to 22C illustrate arrangement patterns of the coloredlayers R, G, and B (filter elements);

[0067]FIGS. 23A to 23C illustrate the process of fabricating a templateprovided with concavities in the surface thereof;

[0068]FIGS. 24A and 24B illustrate the rest of the process offabricating a template provided with concavities in the surface thereof;

[0069]FIGS. 25A and 25B illustrate the process of fabricating a colorfilter of an eighth embodiment;

[0070]FIGS. 26A and 26B illustrate a ninth embodiment of the presentinvention;

[0071]FIGS. 27A to 27C illustrate separation states of the ninthembodiment; and

[0072]FIG. 28 is a cross-sectional view through a liquid crystal panel.

BEST MODE FOR CARRYING OUT THE INVENTION

[0073] Preferred embodiment of the present invention are described belowwith reference to the accompanying drawings.

First Embodiment

[0074] The process of making a template of a first embodiment of thepresent invention is shown in FIGS. 1A to 1E. This method is describedin detail below.

[0075] First of all, as shown in FIG. 1A, a resist layer 20 is formed ona substrate 19.

[0076] The surface of the substrate 19 will be etched to form atemplate, and a silicon wafer is used in this case. The technology ofetching a silicon wafer is established in the art of makingsemiconductor devices and enables highly precise etching to be carriedout. It should be noted that as long as the substrate 19 is of amaterial which can be etched, it is not restricted to being a siliconwafer, and for example a plate or film of glass, quartz, resin, metal,ceramic, or other material may be used therefor.

[0077] As the material forming the resist layer 20, it is possible touse a commercially available positive resist such as that generally usedin the fabrication of semiconductor devices, being a cresol novolac typeresin to which a diazonaphthoquinone derivative is added as aphotosensitive material. Here, positive resist refers to a substancewhich can be selectively removed by developer in an area which isexposed to radiation in accordance with a predetermined pattern.

[0078] As the method of forming the resist layer 20, it is possible touse a spin-coating, dipping, spray-coating, roll-coating, or bar-coatingmethod, for example.

[0079] Next, as shown in FIG. 1B, a mask 21 is disposed on the resistlayer 20, and selected regions only of the resist layer 20 are exposedthrough the mask 21 to radiation 22 to form radiation-exposed regions23.

[0080] The mask 21 is patterned so as to pass the radiation 22 only inthose regions that do not correspond to protrusions 13 shown in FIG. 1E.

[0081] These protrusions 13 are intended to function as a means oftransferring ink filling concavities 15 for forming each color patternlayer 16 (see FIG. 2E) for the color filter being fabricated, and areformed to correspond to the form and layout of the color pattern layer16. For a 10-inch VGA type of liquid crystal panel, for example,approximately 900,000 pixels (for 640×480×3 colors), or in other wordsapproximately 900,000 protrusions 13, are formed at a pitch ofapproximately 100 μm on the template.

[0082] Light of a wavelength in the region of 200 nm to 500 nm ispreferably used as this radiation. The use of light in this wavelengthregion makes it possible to utilize photolithography techniques and theequipment therefor that have been established for the process ofmanufacturing liquid crystal panels or the like, thus reducing costs.

[0083] After the resist layer 20 has been exposed to the radiation 22,developing is carried out under predetermined conditions, and, as shownin FIG. 1C, the resist in the radiation-exposed regions 23 only isselectively removed, exposing the substrate 19, while other regionsremain covered by the resist layer 20.

[0084] When the resist layer 20 is patterned in this way, as shown inFIG. 1D, with the resist layer 20 as a mask, the substrate 19 is etchedto a particular depth.

[0085] The method of etching may be wet etching or dry etching, but,depending on the material of the substrate 19, the method of etching andthe conditions may be chosen to be optimum from a consideration of thecross-sectional shape of the etching, the etching rate, surfaceuniformity, and so forth. For controllability, a dry method is superior,and a device using a parallel flat plate reactive ion etching (RIE)method, inductive coupled plasma (ICP) method, electron cyclotronresonance (ECR) method, helicon wave excitation method, magnetronmethod, plasma etching method, ion beam etching method, or the like maybe used, by way of example, and, by varying the type of etching gas, thegas flow rate, the gas pressure, the bias voltage, and other conditions,the protrusions 13 may be formed in an rectangular shape, a taper may beapplied, or the surface may be made rough, to obtain any desired etchingshape.

[0086] Next, after etching is completed, the resist layer 24 is removedas shown in FIG. 1E, and the substrate 19 having the protrusions 13 isobtained, and this forms a template 12. The processing after thetemplate 12 is obtained is shown in FIGS. 2A to 2E.

[0087] First of all, a reinforcing plate 10 is attached to the template12 with an ink filling layer precursor 11 therebetween.

[0088] A glass substrate is generally used as the reinforcing plate 10,but it is not specifically limited thereto provided it can satisfyconditions such as optical transmissivity and mechanical strength thatare required of a color filter. The reinforcing plate 10 may, forexample, be a plate or film of a plastic material such as apolycarbonate, polyarylate, polyether sulfone, amorphous polyolefin,polyethylene terephthalate, or polymethyl methacrylate.

[0089] The ink filling layer precursor 11 is not particularly limited,provided it has sufficient optical transmissivity such that the colorcharacteristics of the color pattern layer 16 are not lost at thethickness of color pattern layer formation regions 17 shown in FIG. 2E,and various materials may be used therefor, but it is preferable that amaterial that can be hardened by the application of energy is used. Sucha material can be handled as a low-viscosity liquid during the formationof a ink filling layer 14, and can readily flow into the most detailedportions of concavities formed between the template 12 and theprotrusions 13 at a normal temperature and a normal pressure.

[0090] The energy applied thereto is preferably at least one of lightand heat. This makes it possible to use a general-purpose exposureapparatus, baking oven, or hotplate, enabling reductions in equipmentcosts and installation space.

[0091] An example of this material is a resin which is hardened byultraviolet rays. Acrylic resins are suitable examples of such resinsthat are hardened by ultraviolet rays. The use of various commerciallyavailable resins and photosensitive materials makes it possible toobtain an acrylic resin which has superlative transparency and which canalso be hardened by a short application of ultraviolet rays.

[0092] As specific instances of the basic composition of acrylic resinshardened by ultraviolet rays may be cited prepolymers, oligomers,monomers, and optical polymerization initiators.

[0093] As prepolymers or oligomers may be used, for example,acrylate-based substances such as epoxy acrylates, urethane acrylates,polyester acrylates, polyether acrylates, and spiroacetal acrylates; ormethacrylate-based substances such as epoxy methacrylates, urethanemethacrylates, polyester methacrylates, and polyether methacrylates.

[0094] As monomers may be used, for example, monofunctional monomerssuch as 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, 2-hydroxyethylacrylate, 2-hydroxyethyl methacrylate, N-vinyl-2-pyrrolidone, carbitolacrylate, tetrahydrofurfuryl acrylate, isobornyl acrylate,dicyclopentenyl acrylate, and 1,3-butanediol acrylate; bifunctionalmonomers such as 1,6-hexanediol diacrylate, 1,6-hexanedioldimethacrylate, neopentylglycol diacrylate, neopentylglycoldimethacrylate, ethylene glycol diacrylate, polyethylene glycoldiacrylate, and pentaerythritol diacrylate; and polyfunctional monomerssuch as trimethylol propane acrylate, trimethylol propanetrimethacrylate, pentaerythritol triacrylate, and dipentaerythritolhexacrylate.

[0095] As optical polymerization initiators may be used, for example,acetophenones such as 2,2-dimethoxy-2- phenylacetophenone; butylphenonessuch as α-hydroxyisobutylphenone andp-isopropyl-α-hydroxyisobutylphenone; halogenated acetophenones such asp-tert-butyldichloroacetophenone, p-tert-butyltrichloroacetophenone, andα,α-dichloro-4-phenoxyacetophenone; benzophenone compounds such asbenzophenone and N,N-tetraethyl-4,4-diaminobenzophenone; benzylcompounds such as benzyl and benzyl dimethyl ketals; benzoin compoundssuch as benzoin and benzoin alkylethers; oxime compounds such as1-phenyl-1,2-propanedion-2-(o-ethoxycarbonyl) oxime; xanthone compoundssuch as 2-methylthioxanthone and 2-chlorothioxanthone; benzoin etherssuch as benzoin ether and isobutyl benzoin ether; and radical generatingcompounds such as Michler's ketone.

[0096] It should be noted that, if necessary to prevent impairment ofhardening by oxygen, amines or other compounds may be added, and, tofacilitate the painting, a solvent ingredient may be added.

[0097] There is no particular restriction on the solvent ingredientadded, and various organic solvents may be used either singly or incombination, such as, for example, propylene glycol monomethyl etheracetate, propylene glycol monomethyl ether, methoxy methyl proprionate,ethyl cellosolve, ethyl cellosolve acetate, ethyl lactate, ethylpyruvinate, ethyl amyl ketone, cyclohexanone, xylene, toluene, or butylacetate.

[0098] A predetermined amount of the ink filling layer precursor 11,consisting of such an acrylic resin hardened by ultraviolet rays or thelike, is dropped onto the reinforcing plate 10, as shown in FIG. 2A.

[0099] The template 12 is then pressed onto the reinforcing plate 10with the ink filling layer precursor 11 therebetween, as shown in FIG.2B, and, after the ink filling layer precursor 11 has spread over apredetermined region, ultraviolet rays are shone thereon from thereinforcing plate 10 side for a predetermined time to harden the inkfilling layer precursor 11 and thus form the ink filling layer 14between the reinforcing plate 10 and the template 12, as shown in FIG.2C.

[0100] To ensure that the ink filling layer precursor 11 spreads overthe predetermined region, a predetermined pressure may be applied to thetemplate 12 if necessary.

[0101] In the above case, the ink filling layer precursor 11 is droppedonto the reinforcing plate 10, but it may equally well be dropped ontothe template 12 or onto both the reinforcing plate 10 and the template12.

[0102] Alternatively, the ink filling layer precursor 11 may be appliedover one or both of the reinforcing plate 10 and the template 12 byusing a spin-coating method, dipping method, spray-coating method,roll-coating method, bar-coating method, or the like.

[0103] The reinforcing plate 10 and the ink filling layer 14 are thenremoved from the template 12 as an integral unit, as shown in FIG. 2D,to obtain the reinforcing plate 10 on which is formed ink filling layer14 having the ink filling concavities 15 in the surface thereof.

[0104] After the ink filling concavities 15 is thus formed on thereinforcing plate 10, each of the ink filling concavities 15 is filledwith a predetermined colored ink as shown in FIG. 2E, to form the colorpattern layer 16.

[0105] There are no particular restrictions on the method used to fillthe ink filling concavities 15 with colored inks, but an inkjet methodis preferred. With an inkjet method, the practical technology that hasbeen developed for inkjet printers can be employed, enabling the fillingoperation to be carried out rapidly and economically, with no ink waste.

[0106]FIG. 3 shows the ink filling concavities 15 being filled with inks26, such as red ink R, green ink G, and blue ink B, by an inkjet head25.

[0107] The head 25 is disposed facing the ink filling concavities 15 onthe reinforcing plate 10, and the colored inks 26 are ejected into theink filling concavities 15 by the head 25.

[0108] The head 25 is for example one developed for an inkjet printer,and may for example be a Piezo Jet Type employing a piezoelectricelement, or a Bubble Jet Type employing electrothermal conversion as anenergy producing element, and the color areas and color pattern can bedetermined as required.

[0109] For example, if the head 25 has twenty ink-ejecting nozzles foreach of R, G, and B, and a drive frequency of 14.4 kHz (14400 ejectioncycles per second), then if three drops of ink are ejected into each ofthe ink filling concavities 29, to eject ink into the ink fillingconcavities 15 of a 10-inch VGA type of color filter havingapproximately 900,000 pixels, the time required is:

900,000×3 drops/(144000 cycles×20 nozzles×3 colors) =approximately 3seconds

[0110] In this case, even when the time for the head 25 to move from oneink filling concavity 15 to the next is included, all of the ink fillingconcavities 15 can be filled with the colored inks 26 in about 2 or 3seconds.

[0111] The inclusion of a solvent component in the colored inks 26ensures that the solvent of the ink is evaporated by thermal processing.

[0112] In this way, as shown in FIG. 2E, the color pattern layer 16 isformed on the reinforcing plate 10, to obtain the completed product 18of a color filter.

[0113] In the above embodiment, a positive resist is used when theprotrusions 13 are formed on the template 12, but equally a negativeresist, such that regions exposed to radiation are rendered insoluble ina developer, and the regions not exposed to radiation are selectivelyremoved by the developer, may be used; in that case, the mask used has apattern which is the inverse of the pattern of the mask 21.Alternatively, instead of using a mask, a laser beam or electron beammay be used to directly expose the resist in a pattern.

Second Embodiment

[0114] The process of fabricating a template of a second embodiment ofthe present invention is shown in FIGS. 4A to 5C.

[0115] First, as shown in FIG. 4A, the resist layer 20 that forms apredetermined pattern is formed on a base plate 27.

[0116] The base plate 27 is not restricted as long as it can fulfill therole of a support during the patterning of the resist layer 20 bylithography, it has properties such as the mechanical strength andchemical resistance necessary for the processing, and it has goodwettability and adhesiveness with respect to the material forming theresist layer 20; for example, a substrate of glass, quartz, resin,silicon wafer, metal, ceramic, or other material may be used as the baseplate 27. A glass template is used in this case, with the surfacethereof being polished to a flat using a cerium oxide type of polishingagent, then washed and dried.

[0117] Since the material and method used for forming the resist layer20 can be the same as those described with reference to the firstembodiment, further description thereof is omitted.

[0118] Next, as shown in FIG. 4B, a mask 28 is disposed on the resistlayer 20 and predetermined regions only of the resist layer 20 areexposed through the mask 28 to the radiation 22 to form theradiation-exposed regions 23.

[0119] The mask 28 is formed in a pattern such that the radiation 22passes only through regions corresponding to the concavities 29, asshown in FIG. 4C.

[0120] The concavities 29 act as indentations for forming theprotrusions 13 of the template 12 (see FIG. 1E). The protrusions 13 ofthe template 12 are designed as a transfer formation for the ink fillingconcavities 15 (see FIG. 2D) for forming the color pattern layer 16 ofthe color filter (see FIG. 2E). Therefore, the concavities 29 have thesame shape and arrangement as the ink filling concavities 15, in otherwords, they are formed to correspond to the shape and arrangement of thecolor pattern layer 16 of the color filter to be fabricated.

[0121] Light of a wavelength in the region of 200 nm to 500 nm ispreferably used as this radiation. The use of light in this wavelengthregion makes it possible to utilize photolithography techniques and theequipment therefor that have been established for the process ofmanufacturing liquid crystal panels or the like, thus reducing costs.

[0122] If development is performed under predetermined conditions afterthe exposure to the radiation 22, only the resist on theradiation-exposed regions 23 is selectively removed, as shown in FIG.4C, to pattern the resist layer 20 and thus form the concavities 29 ontop of the base plate 27.

[0123] Next, a conductive layer 30 is formed on the resist layer 20 andthe base plate 27 as shown in FIG. 5A, to make the surfaces thereofconductive.

[0124] As the conductive layer 30, Ni formed to a thickness of 500 to1000 Angstroms (10⁻¹⁰m) may be used. for example. The method of formingthe conductive layer 30 may be a method such as sputtering, CVD, vapordeposition, or nonelectrolytic plating.

[0125] Then, using the base plate 27 and the resist layer 20, which havebeen made conductive by the conductive layer 30, as the cathode and atip-shaped or ball-shaped Ni as the anode, electroplating is furthercarried out to electrically deposit Ni to make a metal layer 31, asshown in FIG. 5B.

[0126] The following is a specific example of the electrolyte that maybe used: Nickel sulfamate 900 g/l Boric acid 60 g/l Nickel chloride 8g/l Leveling agent 30 mg/l

[0127] Next, the conductive layer 30 and the metal layer 31 areseparated from the base plate 27, as shown in FIG. 5C, and are washed ifnecessary, to form the template 12.

[0128] Note that the conductive layer 30 may be removed from the metallayer 31 by performing separating processing, if necessary.

[0129] Once the template 12 is obtained in this manner, the color filtercan then be obtained by the steps shown in FIG. 2

[0130] In the present embodiment too, a negative resist may also beused, in which case a mask having a pattern that is the inverse of themask 28 may be used, in other words, a mask that is the same as the mask21 of FIG. 1B. Alternatively, no mask is used and the resist is exposeddirectly in a pattern by laser light or an electron beam.

[0131] Once the template 12 has been fabricated by the above describedmethod of making a color filter, it can be used a number of timeslimited only by its endurance to fabricate two or more color filters,thus reducing the number of steps and the cost.

[0132] A BM or over-coating layer is subsequently formed on top of thecolor pattern layer 16 if necessary, a transparent electrode and anorientation film are attached thereto, and it is installed into an array

Third Embodiment

[0133] A third embodiment of the present invention is intended tofabricate a color filter by a small number of steps, whereby an opaquelayer, in other words, a black matrix is formed by providing ink fillinglayers after a template has been filled with an opaque material.

Color Filter Fabrication

[0134] A plan view of a color filter fabricated by the method of thepresent invention is shown in FIG. 6. As shown in this figure, a colorfilter 101 of the present invention is provided with color patternlayers 111R, 111G, and 111B within pixel aperture portions that areseparated by an opaque layer 115 formed on an ink filling layer 110.

[0135] The ink filling layer 110 may be formed of a material such asresin, for example, with the opaque layer 115 (see FIG. 10) that isformed of an opaque material being provided on a surface thereof (thesurface that can be seen in FIG. 6).

[0136] The color pattern layers 111R, 111G, and 111B combine colorpattern layers of a plurality of primary colors to form individual colorpixels. In the present embodiment, pixels of a color pattern layer (red)111R, a color pattern layer (green) 111G, and a color pattern layer(blue) 111B are arrayed to form individual color pixels, to form colorpixels from the three primary colors of red, green, and blue. The colorpixels in this figure are shown as an array of five columns by fourrows, to simplify the description, but the pixel arrangement in areal-life product will match the resolution of the liquid crystal panel.

[0137] These color pattern layers 111R, 111G, and 111B are formed byinjecting colored inks that are transparent. The pixels are arrayed at apitch of, for example, approximately 100 μm.

[0138] Note that the arrangement of pixels and the pattern of the inkfilling layer 110 are not limited to those shown in FIG. 6; they can beimplemented in various different forms corresponding to the pixel arrayof the liquid crystal panel.

[0139] If a color filter of the above described configuration isinstalled in a liquid crystal panel, light from each pixel of the liquidcrystal panel will pass through and shine from one of the color patternlayers 111R, 111G and 111B. A color display is achieved by attaching thecolor filter to a liquid crystal panel with the colors of the colorpattern layers 111R, 111G, and 111B in the color filter placed incorrespondence with the color disposition of pixels in the liquidcrystal panel.

Fabrication Method

[0140] The method of making a color filter in accordance with thepresent embodiment will now be described with reference to FIGS. 7A to10. These figures are schematic cross-sectional views of the fabricationprocess, taken along the line A-A of FIG. 6.

Template Fabrication

[0141] When it comes to fabricating the color filter of the presentinvention, a template used for transferring the shape of the colorpattern layers of the color filter is first formed. FIGS. 7A to 7E arecross-sectional views of the fabrication process, illustrating themethod of fabricating the template.

Resist Layer Formation Step (FIG. 7A)

[0142] In a resist layer formation step, a resist layer 121 is formed ona substrate 120. Silicon or quartz is preferably used as the material ofthe substrate 120.

[0143] Of resist materials used to configure the resist layer 121, anegative material is one that is converted into a hard film that is madenot soluble in a developer by illuminating it with light of at least acertain strength, and a positive material is one that is made readilysoluble to a developer by illuminating it with light of at least acertain strength. A positive resist material is used in the presentembodiment.

[0144] The method used for making the resist layer 121, is notparticularly limited. For example, a resist material could be coated toa thickness of approximately 1 μm on the substrate 120 by a spin-coatingmethod, then it is fixed by thermal processing to form the resist layer121.

Exposure Step (FIG. 7B)

[0145] In an exposure step, the resist layer 121 is covered with a mask123 in accordance with a predetermined pattern, then light 122 is shonethereon to expose the resist.

[0146] The mask 123 is a screening member that is patterned in such amanner that the light 122 passes therethrough only in regionscorresponding to light-exposed regions 124. This pattern is formed inthe shape of the ink filling layer 110 that separates the pixels of thecolor filter 101.

Development Step (FIG. 7C)

[0147] In a development step, the resist material is removed from thelight-exposed regions 124 by development performed under fixedconditions, after the resist layer 121 has been exposed by the light122. This processing selectively removes the resist material from thelight-exposed regions 124 that had been exposed to the light 122, toreveal the substrate 120.

Etching Step (FIG. 7D)

[0148] In an etching step, concavities 114 are formed in the shape ofthe ink filling layer 110, by etching the patterned resist layer 121with an etchant 125.

[0149] A wet method or a dry method could be used as the etching method.The optimal method and etching conditions are selected to suit thematerial properties of the substrate 120 from the viewpoints of factorssuch as etching cross-sectional shape, etching rate, and surfaceuniformity. If control over etching depth and shape is important, a drymethod is superior.

Removal Step (FIG. 7E)

[0150] In a removal step the resist layer 121 is removed from thesubstrate 120 after the etching. The concavities 114 corresponding tothe pattern shape of the mask 123 have been formed in the substrate 120once the resist layer 121 has been removed. In other words, thesubstrate 120 becomes a template 102.

Color Filter Fabrication

[0151] The description now turns to the method of fabricating a colorfilter using the template 102 formed as described above, with referenceto FIGS. 8A to 8D.

Opaque Layer Formation Step (FIG. 8A)

[0152] In a opaque layer formation step, the concavities 114 of thetemplate 102 are filled with an opaque material to form the opaque layer115 that acts as a black matrix. The opaque material could be any ofvarious different materials, provided it is not optically transmissiveand it is durable. For example, a black resin such as negative resinblack produced by Fuji Hanto, resist HRB-#01 for highly insulating blackmatrices produced by Toppan Printing Co., Ltd., or resin black producedby Japan Synthetic Rubber (JSR) Co., Ltd. could be used dissolved in anorganic solvent. In the present embodiment, ink is ejected from aninkjet type of recording head, so it is necessary to ensure theliquidity of the opaque material to a certain extent. The type oforganic solvent is not particularly limited, so various differentorganic solvents could be used. For example, propylene glycol monomethylether acetate, propylene glycol monopropyl ether, methoxy methylproprionate, methoxy ethyl proprionate, ethyl cellosolve, ethylcellosolve acetate, ethyl lactate, ethyl pyruvinate, methyl amyl ketone,cyclohexanone, xylene, toluene, or butyl acetate could be used therefor,either singly on in a combination of a plurality of substances.

[0153] The method of applying the opaque material involves ejecting froman inkjet head 103 an opaque ink 115 a consisting of an opaque materialthat is dissolved or dispersed in an organic solvent, as shown in FIG.9. During this time, the position at which the opaque ink 115 a hits iscontrolled by controlling the movement of the head 103 in the directionshown by the arrows in the figure, for example, in such a manner that auniform quantity of the ink 115 a fills each of the concavities 114formed in the template 102. Once all of the concavities 114 have beenfilled uniformly with the ink 115 a, the filling ends. If an ink 115 acomprising a solvent component is used, that solvent component isremoved by thermal processing. Note that, since the opaque layer 115contracts due to the removal of the solvent component, it is necessaryto apply a sufficient quantity of the ink 115 a to ensure that thethickness that remains after the contraction can ensure the requiredopacity.

Ink Filling Layer Formation Step (FIG. 8B)

[0154] In an ink filling layer formation step, an ink filling layerprecursor is coated onto the template 102 on which is formed the opaquelayer 115, to form the ink filling layer 110. First of all, the inkfilling layer precursor is coated onto the surface of the template 102that is provided with the concavities 114. Next, after a reinforcingplate 116 has been attached to the ink filling layer precursor coated onthe template 102, hardening processing is performed to correspond to theink filling layer precursor that is used, to form the ink filling layer110. If, for example, a resin that is hardened by ultraviolet rays isused for the ink filling layer precursor, ultraviolet rays are shonefrom the reinforcing plate 116 side for a predetermined time to causethe resin to harden and thus form the ink filling layer 110.

[0155] Any well-known method can be used for coating the ink fillinglayer precursor, such as a spin-coating method, dipping-method,spray-coating method, roll-coating method, or bar-coating method.

[0156] In this case, it is preferable that the ink filling layerprecursor that is coated onto the template 102 is a material that ishardened by the application of at least one of light and heat. Thismakes it possible to use a general-purpose exposure apparatus, bakingoven, or hotplate, enabling reductions in equipment costs andinstallation space.

[0157] A resin that is hardened by ultraviolet rays is particularlypreferable as the material of the ink filling layer 110. Morespecifically, it is preferable to use an acrylic resin that is hardenedby ultraviolet rays, as it is commercially available on the market and aphotosensitive material is easy to obtain.

[0158] Since the reinforcing plate 116 is used with the objective ofreinforcing the color filter, it is selected in accordance with thecolor filter that is to be fabricated. A substance that has a suitablemechanical strength and also has a high level of optical transmissivityto enable sufficient light from the display panel to pass therethroughmay be used as the reinforcing plate 116. For example, a glass substrateor a substrate or film of a plastic such as a polycarbonate,polyacrylate, polyether sulfone, amorphous polyolefin, polyethyleneterephthalate, or polymethyl methacrylate could be used as thereinforcing plate 116.

[0159] Note that, if the reinforcing plate 116 is not necessary forstrengthening the color filter, it may be separated therefrom.

Separation Step (FIG. 8C)

[0160] In a separation step, the hardened ink filling layer 110 isseparated from the template 102. Once the ink filling layer 110 issufficiently hardened, the ink filling layer 110 is firmly attached tothe reinforcing plate 116 and the ink filling layer 110 is also firmlyattached to the opaque layer 115. Therefore, if the reinforcing plate116 is peeled off from the template 102, the reinforcing plate 116, theink filling layer 110, and the opaque layer 115 will be removed as anintegral assembly.

Color Pattern Layer Formation Step (FIG. 8D)

[0161] In a color pattern layer formation step, the ink fillingconcavities 117 of the ink filling layer 110 that has been separatedfrom the template 102 are filled with colored inks 111 a, to form acolor pattern layer 111.

[0162] The method used for applying the colored inks 111 a is notparticularly limited, but an inkjet method that ejects inks from a headcould be used therefor. The colored inks ejected from the head may bethose that are transparent when dry. When ejected from a head, it isparticularly preferable that these inks have a low viscosity and a highdensity, and they are fabricated of colored pigments or dyestuffs thatare mixed into an organic solvent or water.

[0163] With an inkjet method, the inkjet head 103 ejects the coloredinks 111 a corresponding to the primary colors, as shown in FIG. 10, sothat the colored inks 111 a fill the ink filling concavities 117 forforming the pixels allocated to each of the colors. In this figure, ared colored ink R, a green colored ink G, and a blue colored ink B eachhit neighboring columns, by way of example. In an example of thesequence of this filling, the inks fill one column of color pixels whilethe head reciprocates from in front of this figure towards the rearthereof, then the head moves in the direction of the arrows in thefigure and inks fill the neighboring column of color pixels. Repetitionof this sequence makes it possible to form the color pattern layer 111in the ink filling concavities 117.

[0164] Once the colored inks 111 a have been applied, the solventcomponent within the colored inks 111 a is evaporated by thermalprocessing to solidify them. This thermal processing is done by using aheater, for example, to heat the reinforcing plate 116 to apredetermined temperature (such as approximately 70° C.). The volume ofthe color pattern layer 111 formed by the evaporation of the solventfrom the colored inks 111 a is less than before the solvent wasevaporated, as shown in FIG. 8D. If this decrease in volume is toodramatic, the process of ejecting and heating the colored inks 111 a canbe repeated until the thickness of the ink film is sufficient for acolor filter. This processing ensures that the solvent evaporates fromthe colored inks 111 a until finally only the solid portions of thecolored inks 111 a, to form the color pattern layer 111.

[0165] After the color pattern layer 111 has been formed, heating isperformed at a predetermined temperature (for example, 120° C.) for apredetermined time (for example, approximately 20 minutes) in order todry out the colored inks 111 a completely, then a predetermined resin isused to form a protective film (not shown in the figure) to protect andflatten the filter surface. Finally, if transparent electrode areprovided on the protective film, the color filter 101 of the presentinvention is completed.

[0166] Note that colored inks in three primary colors are used in theabove embodiment to fabricate the color filter, but other primary colorscould also be used, depending on factors such as whether an additivecolor process or a subtractive color process is employed. In addition,instead of a color filter, this process can be used to fabrication asingle-color display filter or a display filter that blocks the effectsof ultraviolet rays or the like, by using a colored ink of a singlecolor or an ink in which is mixed a material that has the effect ofblocking ultraviolet rays or the like.

[0167] The resist layer 121 was described above as being formed of apositive resist, but a negative resist could equally well be used. Insuch a case, a mask is used wherein the relationship between exposedportions and non-exposed portions is the inverse of that of the mask123.

[0168] The exposure method could be such that no mask is used and theresist is exposed directly in a pattern by laser light or an electronbeam.

[0169] Since the ink filling layer 110 that separates the pixels of thecolor filter 101 is formed in the present embodiment by a transfermethod after the opaque ink 115 a has been applied, as described above,the opaque layer 115 and the ink filling layer 110 (the separatingmember) can be fabricated simultaneously. This means that the efficiencyof use of materials is higher than that of the conventional art, andalso the number of steps can be reduced. It is therefore possible toreduce the cost of the color filter to less than that in theconventional art.

[0170] In addition, once the template 102 has been fabricated, it can beused repeatedly within the limits of its durability, so that the processof making the template 102 can be omitted for the second and subsequentfilters, further reducing the number of steps and thus making itpossible to reduce the cost of color filters even further.

Fourth Embodiment

[0171] A fourth embodiment of the present invention provides anothermethod of fabricating the template for the above described thirdembodiment.

[0172] In the present embodiment, the fabrication process other that thesteps for forming the template are the same as those of the thirdembodiment, so further description thereof is omitted.

[0173] Cross-sectional views illustrating the method of fabricating thetemplate in accordance with this fourth embodiment are shown in FIGS.11A to 12C.

Resist Layer Formation Step (FIG. 11A)

[0174] In the resist layer formation step, a resist layer 131 is formedon a base plate 130. The material of the base plate 130 is notrestricted so long as it can fulfill the role of a support during thepatterning of the resist layer 131 by lithography, it has propertiessuch as the mechanical strength and chemical resistance necessary forthe processing, and has good wettability and adhesiveness with respectto the resist layer 131. For example, a material such as glass, quartz,silicon wafer, resin, metal, or ceramic could be used as the base plate130. A glass template is used in the present embodiment, with thesurface thereof being polished to a flat using a cerium oxide type ofpolishing agent, then washed and dried.

[0175] Since the material and formation method of the resist layer 131can be considered to be the same as in the above described thirdembodiment, further description thereof is omitted.

Exposure Step (FIG. 11B)

[0176] In the exposure step, the resist layer 131 is covered with a mask133 in accordance with a predetermined pattern, then light 132 is shonethereon to expose the resist.

[0177] The mask 133 is a screening member that is formed in a patternsuch that the light 132 passes therethrough only in regionscorresponding to light-exposed regions 134. This pattern is formed in toallow the light 132 to pass through in regions corresponding to the inkfilling concavities 117 of the pixel region. In other words, therelationship between the regions through which light passes and theregions through which light does not pass is the inverse of that of theabove third embodiment. Of course, if a negative resist is used, thisrelationship is again inverted.

Development Step (FIG. 11C)

[0178] In the development step, the resist material is removed from thelight-exposed regions 134 by development performed under fixedconditions, after the resist layer 131 has been exposed by the light132. This processing selectively removes the resist material from thelight-exposed regions 134 that had been exposed to the light 132, toreveal the base plate 130.

Conductivity Step (FIG. 12A)

[0179] In a conductivity step, a conductive layer 135 is formed on thebase plate 130 to make the surface thereof conductive.

[0180] A material that is provided with electrical conductivity forpromoting the growth of a plated (metal) layer 136 as shown in FIG. 12Bis sufficient as the material of the conductive layer 135, such as Niformed to a thickness of 500 to 1000 Angstrom (10⁻¹⁰m). Any of variousmethods could be used for forming the conductive layer 135, such assputtering, CVD, vapor deposition, or nonelectrolytic plating. Note thatif it is possible to grow the plated layer 136 without using theconductive layer 135, this step is unnecessary.

Plated (Metal) Layer Formation Step (FIG. 12B)

[0181] In a plated layer formation step, the plated layer 136 is grown.First of all, the resist layer 131 and the base plate 130, which havebeen made conductive by the conductive layer 135 are used as the anodeand a tip-shaped or ball-shaped Ni is used as the anode, connected tothe electrodes of a plating device that is not shown in the figures. Niis electrodeposited by this electroplating method to form the platedlayer 136.

[0182] A plating liquid of the following composition may be used as theelectrolyte: Nickel sulfamate 500 g/l Boric acid 30 g/l Nickel chloride5 g/l Leveling agent 10 mg/l

Separation Step (FIG. 12C)

[0183] In the separation step, the conductive layer 135 and the platedlayer 136 are separated from the base plate 130 and the resist layer131. After the separation, a template 102 b can be completed by washingit if necessary. Note that the conductive layer 135 could be removedfrom the plated layer 136 by separation processing, if necessary.

[0184] If the template 102 b that has been fabricated as described aboveis used as the template of the third embodiment, the color filter of thepresent invention can be fabricated therefrom. Details of the method offabricating this color filter are similar to those of the thirdembodiment.

[0185] Note that the resist layer 131 was described above as beingformed of a positive resist, but a negative resist could equally well beused. In such a case, a mask is used wherein the relationship betweenexposed portions and non-exposed portions is the inverse of that of themask 133

[0186] In addition, the exposure method could be such that no mask isused and the resist is exposed directly in a pattern by laser light oran electron beam

[0187] With the present embodiment as described above, a templatesuitable for forming a color filter can be fabricated by electroplating.The form of this template is similar to that of the third embodiment, soit can achieve effects similar to those of the third embodiment asdescribed above. In addition, since the template fabricated by thepresent embodiment is of metal and thus is rigid, it is durable and alsohas the effect of reducing fabrication costs even further.

Fifth Embodiment

[0188] In the above described third embodiment, the concavities 114formed in the template 102 have inner side surfaces that are shaped todescend at right angles, parallel to each other. In addition, if theconcavities 114 are filled with an opaque material and resin to form theopaque layer 115 and the ink filling layer 110, the shape of theresultant concavities 117 is also such that the inner side surfacesthereof descend at right angles, as shown in FIG. 13B.

[0189] With concavities 114 and 117 of this shape, increasing the pixeldensity of the liquid crystal panel will restrict the surface area ofaperture portions, which is thought to make it difficult for the ink 115a forming the opaque layer 115 or the colored inks 111 a (see FIG. 10)forming the color pattern layer 111 to hit them.

[0190] Thus the inner side surface of concavities provided in thetemplate of the present embodiment are formed inclined, in a taperedshape. For example, concavities 114 b formed in a template 102 c shownin FIG. 14A are tapered so that the inner side surfaces thereof areinclined. If these concavities 114 b have inner side surfaces that areinclined in this manner, the surface area of each aperture portionthereof is broader than the base surface, so that the concavities 114 bcan be filled reliably with the opaque ink 115 a even when the pixeldensity is increased. This also facilitates the separation of an opaquelayer 115 b and an ink filling layer 110 b from the template 102 c.

[0191] If such a template 102 c is used to form the opaque layer 115 band the ink filling layer 110 b, the shape of resultant concavities 117b will also be tapered.

[0192] The configuration could also be such that tapering is providedonly at the aperture edge portions of the inner side surfaces of theconcavities 114 b in the template 102 c. For example, a tapered shapecould be formed only at aperture edge portions of concavities 114 c in atemplate 102 d, as shown in FIG. 15A. If the concavities 114 c areformed in this manner so that the aperture edge portions are tapered,the surface area of each aperture portion of the concavities 114 c isbroader than the base surface thereof, so that the concavities 114 c canbe filled reliably with the opaque ink 115 a even when the pixel densityis increased.

[0193] In particular, if the concavities 114 c provided with taperingonly at aperture edge portions are used, this has the effect of makingit difficult for color unevenness to occur at peripheral regions of acolor pattern layer 111 c within the side walls of an ink filling layer110 c transferred from these concavities 114 c. In other words, the inkfilling layer 110 c that is transferred from the concavities 114 cprovided with a tapered shape only in aperture edge portions thereofwill have tapering only at the bases of the side walls thereof, as shownin FIG. 15B. If this color pattern layer 111 c is viewed from theobservation direction (from above, in these figures), there is only asmall difference between the thickness d2 of the color pattern layer 111c at portions that are tapered and the thickness d1 thereof at portionssome distance from the bases of the side walls. Since any difference inthickness in the color pattern layer 111 c is observed as a differencein color tone or brightness, minimizing this difference in thicknesscontrols any color irregularities due to differences in color tone orbrightness to be as small as possible. If the slope of the tapering atthe aperture edge portions of the concavities 114 c is made gentleenough that the opaque ink 115 a (see FIG. 13A) is guided into theconcavities 114 c, this difference in thickness can be reduced evenfurther so that there is substantially no color unevenness.

[0194] If the present embodiment is configured as described above, theside surfaces of the concavities of the template are inclined to form atapered shape so that the opaque ink can be guided reliably and easilyinto the concavities. This facilitates control over the head, which hasthe effect of improving the yield during manufacture. In particular, ifonly the aperture edge portions of the concavities are provided with atapered shape, this makes it possible to suppress any color unevennessin the color filter to a minimum.

Sixth Embodiment

[0195] The present embodiment involves a method of making a color filterwherein a surface of a protective film is flattened to correspond to anoptically transmissive region of a colored layer by forming a protectivefilm with the aid of a template provided with a surface that is flat inat least a predetermined region, when that protective film is formed ona colored layer after that colored layer has been formed by a pigmentdispersion method. Note that the present embodiment is not limited to acase in which the colored layer is formed by a pigment dispersionmethod; it can also be applied to color pattern layers formed inaccordance with any of the previous embodiments. In other words, thepresent embodiment can be used regardless of the method used for formingthe colored layer (color pattern layer).

Color Filter Fabrication Process

[0196] The present embodiment is described below with reference to FIGS.16A to 16c. In this case, FIGS. 16A to 19 C are cross-sectional views ofthe process of fabricating the color filter.

Black Matrix Formation Step (FIG. 16A)

[0197] A layer that is opaque, such as a layer of chrome, is formed to apredetermined thickness (such as 0.15 μm) by a method such as sputteringon a transparent reinforcing plate 211 that acts as a foundation for thecolor filter, then a resist layer (not shown in the figure) is furtherformed thereon. Next, this resist layer is exposed in accordance with apredetermined pattern, then the resist layer is developed to pattern.The thus patterned resist layer is used as a mask for etching the chromelayer, then the resist layer is removed to form an opaque patternedlayer, in other words, an opaque layer (black matrix) 213.

[0198] Note that opaque layer 213 can be configured as a deposition ofchrome and chrome oxide so that it reduces reflection by means of lightinterference effect.

[0199] A polyimide resin or an acrylic resin in which is dispersed ablack dyestuff, black pigment, carbon black, or the like could be usedas the material of the opaque layer 213.

Colored Photosensitive Resin Layer R Coating Step (FIG. 16B)

[0200] A photosensitive resin that is colored red R, by dispersing apigment used as a coloring material in a resin such as a polyimide, iscoated on the reinforcing plate 211 on which is formed the opaque layer213, to form a colored photosensitive resin layer 215 a. A spin-coatingmethod, roll-coating method, or dipping method could be used as thiscoating method. The thickness of the colored photosensitive resin layer215 a is determined by the color characteristics that are required, andis on the order of 1 to 2 μm.

Exposure Step (FIG. 16C)

[0201] Predetermined regions of the colored photosensitive resin layer215 a are exposed through a mask 212, as shown in FIG. 16C. The mask 212is patterned in such a manner that light passes therethrough only inregions corresponding to a red color pattern of the color filter beingfabricated.

Development Step (FIG. 17A)

[0202] Regions other than the light-exposed regions of the exposure stepare removed by a developer, to form a colored layer R. An alkalineaqueous solution of tetramethyl ammonium hydroxide, sodium hydroxide,potassium hydroxide, calcium hydroxide, or trisodium phosphate mixedwith sodium silicate could be used as the developer.

Colored Layers G and B Formation Steps (FIG. 17B)

[0203] Colored layers G and B are formed in a similar manner to theformation of the colored layer R, by repeating each of the coloredphotosensitive resin layer coating step, exposure step, and thedevelopment step, as shown in FIG. 178.

Protective Film Precursor Layer Formation Step (FIGS. 17C to 18B)

[0204] A protective film precursor 217 a is dropped on top of thecolored layers R, G, and B, as shown in FIG. 17C. The composition of theprotective film precursor 217 a is not particularly limited, provided itcan function as a protective film without affecting the opticaltransmissivity and color characteristics required of the color filter,once it is turned into the protective film, and thus various differentresin, glass, or ceramic materials can be used therefor.

[0205] In addition, the protective film precursor 217 a is preferably ofa material which can be hardened by the application of energy. With sucha property, the protective film precursor 217 a will form a solid filmwhen turned into the protective film, increasing the reliability of thisprotective film.

[0206] The energy applied thereto is preferably one or both of light andheat. This makes it possible to use a general-purpose exposureapparatus, baking oven, or hotplate, enabling a reduction in equipmentcost and improving the mass-productivity. The protective film precursor217 a could be selected from the materials that can be used for the inkfilling layer precursor 11 of the first embodiment.

[0207] A protective film precursor layer 217 b is formed within apredetermined region by attaching a template 219, which has a flatsurface corresponding at least to the colored layers R, G, and B (filterelements), to the protective film precursor 217 a that has been droppedon the colored layer, and pressing down so as to spread the precursor,as shown in FIG. 18B. In this case, it is desirable that the flatness ofthe surface of the template 219 is highly precise. More specifically,the roughness of the template 219 should be within ±0.1 μm.

[0208] In this step, the protective film precursor could be attached tothe template 219 by using a method such as spin-coating or roll-coatingto apply it beforehand to either the colored layers R, G, and B or thetemplate 219.

Protective Film Precursor Layer Hardening Step (FIG. 18C)

[0209] After the protective film precursor layer 217 b has been formedover the predetermined region, the protective film precursor layer 217 bis hardened by processing appropriate to the material thereof, to obtaina protective film 217 c. Since an acrylic resin hardened by ultravioletrays is used in the present embodiment, the protective film precursorlayer 217 b is hardened by illuminating it with ultraviolet rays underpredetermined conditions.

Template Separation Step (FIG. 19A)

[0210] After the protective film 217 c has been formed, the template 219is separated from the reinforcing plate 211, as shown in FIG. 19A.

Transparent Electrode Formation Step (FIG. 19B)

[0211] Next, a transparent electrode 221 a is formed over the entiresurface of the protective film 217 c by a well-known method such assputtering or vapor deposition. A material provided with both opticaltransmissivity and electrical conductivity can be used as the materialof the transparent electrode 221 a, such as indium tin oxide (ITO) or acomposite oxide such as indium oxide and zinc oxide.

Patterning Step (FIG. 19C)

[0212] If metal-insulator-metal (MIM) technology, using alternate layersof metal and an insulator, is employed as the method of driving theliquid crystal panel, the transparent electrode 221 a is then patterned.

[0213] Alternatively, if a method such as thin film transistors (TFTs)is used for driving the liquid crystal panel, this step is notnecessary.

[0214] The configuration of the present embodiment makes it possible toflatten the surface of the protective film in a highly precise manner,so that the voltage applied to common electrodes formed on thatprotective film can be made uniform. If a simple matrix drive method isused for the liquid crystal panel, therefore, the occurrence ofcrosstalk can be suppressed.

[0215] In addition, the present embodiment makes it possible to suppressvariations in the surface resistance of common electrodes (ITO film)formed on the protective film, thus making it possible to preventdisplay variations in the liquid crystal panel.

Seventh Embodiment

[0216] In the present embodiment, a protective film and spacers for acolor filter are formed integrally by a template provided withconcavities at predetermined positions on a surface, and the spacers aredisposed at suitable positions.

Color Filter Formation Step

[0217] The present embodiment is described below with reference to FIGS.20A to 21C. In this case, FIGS. 20A to 21C are cross-sectional views ofsteps in the formation of the color filter. It should be noted, however,that since the steps up until the formation of the opaque layer (blackmatrix) and the colored layer on the substrate are the same as those ofthe sixth embodiment, further description thereof is omitted.

Protective Film Precursor Layer Formation Step (FIG. 20A and FIG. 20B)

[0218] A protective film precursor 218 a is dropped onto the coloredlayers R, G, and B, as shown in FIG. 20A. The composition of theprotective film precursor 218 a must fulfill the function of aprotective film without affecting the optical transmissivity and colorcharacteristics required of the color filter, when it has been hardenedin the subsequent step (to form the protective film). Damage to othercomponents such as a TFT array can be prevented by also providing thisprotective film with the suitable strength and elasticity required ofspacers 218 d (see FIG. 21A). It is preferable that the coefficient ofthermal expansion thereof is determined from consideration of volumetricchanges due to any difference in the coefficients of thermal expansion,to ensure that the reliability of the liquid crystal panel is notaffected by damage to the orientation film or the colored layer. Thecomposition of the protective film precursor 218 a having suchcharacteristics is the same as that of the sixth embodiment.

[0219] Next, as shown in FIG. 20B, a template 220 provided withconcavities 220 b at predetermined positions in a flat surface thereof(details of the fabrication of this template will be given later) isattached to the protective film precursor 218 a that has been dropped onthe colored layers R, G, and B, then is pressed to form a protectivefilm precursor layer 218 b. The depth of the concavities 220 b formed inthe template 220 corresponds to the height of the spacers 218 d (seeFIG. 21A) and is processed in accordance with the liquid crystal panelbeing fabricated. For a VGA type of liquid crystal panel using TFTs asdrive elements, for example, this depth is on the order of 2 to 6 μm.The concavities 220 b are preferably located at positions that cross thelattice-like opaque layer (black matrix) 214, as shown in FIGS. 22A to22C. Such a configuration makes it possible for the spacers 218 d to beprovided protruding easily at positions crossing the lattice-like opaquelayer 214. Therefore, the spacers 218 d are not disposed on the coloredlayers R, G, and B (filter elements), making it possible to improve theyield of manufactured color filters. In addition, the effects onorientation variations of the liquid crystal and the polarizationcharacteristics of the liquid crystal panel caused by the spacers 218 dcan be reduced by providing the spacers 218 d protruding above theopaque layer 214, so that the image quality of the liquid crystal panelcan be maintained in a desirable state.

[0220] Any shape such as circular cylindrical or square cylindrical canbe used as the shape of the concavities 220 b, but a circularcylindrical shape is particularly preferable. Disturbances in theorientation of the liquid crystal can be suppressed by forming thespacers 218 d of a circular cylindrical shape.

[0221] Furthermore, it is not necessary to dispose the spacers 218 d atall of the lattice points of the opaque layer (black matrix) 214; theymay be disposed at only a few desired lattice points. It should benoted, however, that it is necessary to dispose the spacers 218 d insuch a manner that a necessary strength is achieved, in order tomaintain a uniform cell gap. The disposition of the spacers 218 d ispreferably within a range of 100 to 200 μm, for example.

[0222] The pattern in which the colored layers R, G, and B (filterelements) are disposed is not limited to a mosaic array as shown in FIG.22A, but it could also be a triangular array as shown in FIG. 22B or astrip array as shown in FIG. 22C. In such a case, the spacers 218 d canbe disposed protruding from any desired position on the opaque layer(black matrix) 214. Note that the disposition patterns of the spacers218 d are shown in these figures by way of example and the presentinvention is not limited thereto.

Protective Film Precursor Layer Hardening Step (FIG. 20C)

[0223] After the protective film precursor layer 218 b has been formedover the predetermined region, the protective film precursor layer 218 bis hardened in accordance with the composition thereof. This step causesthe protective film precursor layer 218 b to harden to form a protectivefilm 218 c. If an acrylic resin which is hardened by ultraviolet rays isused as the protective film precursor layer 218 b, for example,ultraviolet rays are shone onto the protective film precursor layer 218b under predetermined conditions to harden it.

Template Separation Step (FIG. 21A)

[0224] After the protective film precursor layer 218 b has hardened, thetemplate 220 is separated from the protective film 218 c. The protectivefilm 218 c on which the spacers 218 d are formed integrally above thecolored layers R, G, and B can thus be obtained.

Transparent Electrode Formation Step (FIG. 21B)

[0225] Next, transparent electrodes 222 are formed on the protectivefilm 218 c. This step uses a well-known method such as sputtering orvapor deposition to form the transparent electrodes 222 over the entiresurface of the protective film 218 c. A material provided with bothoptical transmissivity and electrical conductivity can be used as thematerial of the transparent electrodes 222, such as indium tin oxide(ITO) or a composite oxide such as indium oxide and zinc oxide.

Patterning Step (FIG. 21C)

[0226] If metal-insulator-metal (MIM) technology, using alternate layersof metal and an insulator, is employed as the method of driving theliquid crystal panel, resist (not shown in the figure) is coated overthe transparent electrodes 222 and the transparent electrodes 222 arepatterned to a desired shape by etching.

[0227] Alternatively, if a method such as thin film transistors (TFTs)is used for driving the liquid crystal panel, this step is notnecessary.

[0228] If the transparent electrodes 222 on the spacers 218 d causeproblems, the transparent electrodes 222 are removed from the tops ofthe spacers 218 d by etching, using a method similar to those describedabove. Note that the transparent electrodes 222 need not be removed fromon top of the spacers, but only if no problems are caused by leaving thetransparent electrodes 222 on top of the spacers 218 d.

Template Fabrication Process

[0229] The process of fabricating the template 220 used in the presentembodiment will now be described, with reference to FIGS. 23A to 23C.

Resist Layer Formation Step (FIG. 23A)

[0230] Resist is coated over a substrate 220 a made of quartz, to form aresist layer 226. As long as the substrate 220 a is of a material whichcan be etched, it is not restricted to quartz, and glass, silicon singlecrystal, metal, ceramic, resin, or other material may be used therefor.The composition of the resist layer 226 could be one that is generallyused in the fabrication of semiconductor devices, for example, acommercially available positive resist which is a cresol novolac typeresin to which a diazo-naphthoquinone derivative is added as aphotosensitive material. In this case, the positive resist is a materialthat can be selectively removed by a developer in exposed regions. Thethickness of the resist layer 225 is sufficient to provide the necessarythickness to enable it to act as an etching mask in the subsequentetching step, which is roughly 1 to 3 μm.

Resist Layer Exposure Step (FIG. 23B)

[0231] A mask 212 a is placed on the resist layer 226, then the resistlayer 226 is exposed in a desired pattern through the mask 212 a. Themask 212 a is formed in a pattern such that light passes therethroughonly in regions corresponding to the concavities 220 b shown in FIG.20B, in other words, the previously described spacers 218 d.

Development Step (FIG. 23C)

[0232] If development with a developer is done after the exposure, theresist is selectively removed only in regions that were exposed in theexposure step, to reveal the substrate 220 a as shown in FIG. 23C, withthe other regions remaining covered by the resist layer 226. An alkalineaqueous solution of tetramethyl ammonium hydroxide, sodium hydroxide,potassium hydroxide, calcium hydroxide, or trisodium phosphate mixedwith sodium silicate could be used as the developer.

Etching Step (FIG. 24A)

[0233] The substrate 220 a is etched to a predetermined depth, using thepatterned resist layer 226 as a mask. Details of the etching method areas previously described for the first step, and the concavities 220 bcould be made square or tapered. The depth of the etching corresponds tothe depth of the spacers to be formed. which is roughly 2 to 6 μm.

Resist Layer Separation (FIG. 24B)

[0234] When the depth of the concavities 220 b has reached apredetermined depth, the etching is stopped and the resist layer 226 ispeeled off.

[0235] In this manner, the depth of the concavities 220 b of thetemplate 220 can be controlled very accurately by the etching technique.For example, etching errors are ±0.05 μm for a concavity depth of 3 μm.Therefore, the height of the spacers, in other words, the cell gap, canbe kept constant and thus it can easily be maintained at a value that issuitable for the retardation of the liquid crystal.

[0236] If, for example, natural light is incident on an STN liquidcrystal panel from above, light passing through a first polarizationfilm is polarized linearly and light passing through a secondpolarization film is polarized circularly by the multiple refractionsdue to the liquid crystal molecules. The shift in this phase depends onthe retardation and which is the product of the difference an betweenthe refractive indices along the long and short axes of the liquidcrystal molecules and the thickness (cell gap spacing) d of the liquidcrystal layer. The magnitude of this retardation is an important factorin the design of the liquid crystal panel. With normally-black mode, forexample, it is known that if the magnitude of the retardation falls to0.48 μm or less with light of 550 nm, the contrast will suddenlydeteriorate due to leakage of this light. With the present embodiment,not only can the positions of the spaces be adjusted easily, but alsothe height of the spacers (cell gap spacing) d can be made uniform, sothat the magnitude of the retardation can be maintained at a suitablevalue. It is therefore possible to easily adjust the displaycharacteristics of the liquid crystal, such as optical transmissivity,contrast ratio, and response speed.

[0237] In addition, since the protective film and spacers of the presentembodiment can be formed as an integral assembly, there is no danger ofimpurities (particularly impurities such as ions) becoming mixed intothe liquid crystal due to dispersion of the spacers, as in theconventional art. Therefore, when a voltage is applied to the liquidcrystal sandwiched between a transparent electrode and a commonelectrode, to change the arrangement of the liquid crystal, the lack ofimpurities mixed into the liquid crystal makes it possible to ensuregood drive characteristics for the liquid crystal.

Eighth Embodiment

[0238] The process of fabricating a color filter in accordance with aneighth embodiment is shown in FIGS. 25A and 25B.

[0239] The present embodiment is applicable instead of the step of thesixth embodiment shown in FIG. 18A. In other words, the steps shown inFIGS. 16A to 17C are performed in the same manner as in the sixthembodiment, then the step shown in FIG. 25A is performed. The step shownin FIG. 25A differs from that shown in FIG. 18A in that a transparentelectrode film 300 is formed on a template 302 beforehand. A colorfilter with attached transparent electrode film 300 is obtained byseparating the template 302 from the transparent electrode film 300, asshown in FIG. 25B.

[0240] Note that the combination of materials configuring the template302 and the transparent electrode film 300 may cause problems such asincreasing the adhesive forces therebetween so that it is difficult forthe transparent electrode film 300 to separate from the template 302.This increases the defective product ratio due to faults such as errorsor cracking in the transparent electrode film 300, reducing themass-productivity because of the time required for the separation, orreducing the durability of the template 302.

[0241] To this end, radiation 306 is shone through the template 302 ontothe interface between the transparent electrode film 300 and thetemplate 302, as shown in FIG. 25A. This reduces or even destroys theadhesive forces between the transparent electrode film 300 and thetemplate 302, so that the transparent electrode film 300 can separateeasily from the template 302, as shown in FIG. 25B.

[0242] More specifically, the various bonding forces between atoms ormolecules are weakened or destroyed at the interface between thetransparent electrode film 300 and the template 302, so that phenomenasuch as ablation occur, leading to interface separation. Alternatively,the radiation 306 vaporizes and releases components within thetransparent electrode film 300, which activates a separation effect andmay even help the interface separation.

[0243] To cause this interface separation due to the illumination of theradiation 306, it is necessary to make the material of the template 302transparent to the radiation 306 and also form the transparent electrodefilm 300 of a material that absorbs the energy of the radiation 306.

[0244] In this case, the transmissivity of the template 302 with respectto the radiation 306 is preferably at least 10%, more particularly atleast 50%. It is preferable that the transmissivity of the radiation 306through the template 302 is made high, to reduce the attenuation of theilluminated radiation 306 as it passes through the template 306. Quartzglass may be cited as an example of the template 302. Quartz glass ishighly transparent to light in the short wavelength region and has asuperlative mechanical strength and thermal resistance.

[0245] Deep UV light could be cited as an example of the radiation 306.The source of this radiation could be an excimer laser, for example,which is used to output a high level of energy in the short wavelengthregion. If an excimer laser is used, ablation is induced only in thevicinity of the interface within an extremely short time, and thetemplate 302 and the transparent electrode film 300 are subjected tosubstantially no temperature shock.

[0246] The surface of the transparent electrode film 300 that has beenseparated from the template 302 is then preferably washed to remove anyportions that have been damaged by the radiation 306.

[0247] The above processing makes it possible to obtain the color filtershown in FIG. 25B. With the present embodiment, the transparentelectrode film 300 is formed beforehand on the template 302, so that theprotective film 217 c and the colored layers R, G, and B are not damagedby processes such as annealing. In addition, the flexibility with whichmaterials are selected is increased because the protective film 217 cand the colored layers R, G, and B are not exposed to high temperaturesduring annealing.

Ninth Embodiment

[0248] A ninth embodiment of the present invention will now be describedwith reference to FIGS. 26A and 26B. In the present embodiment, aseparation layer 304 is formed between the template 302 and thetransparent electrode film 300, as shown in FIG. 26A. In other words,the separation layer 304 is first formed on the template 302, then thetransparent electrode film 300 is formed on top of the separation layer304. The rest of the structure is the same as that of the eighthembodiment.

[0249] When the radiation 306 illuminates the separation layer 304through the template 302, as shown in FIG. 26B, the template 302 and thetransparent electrode film 322 separate readily.

[0250] Various materials can be used as the material of the separationlayer 304, such as various oxide ceramics such as non-crystallinesilicon, silicon oxide, silicate compounds, titanium oxide, titaniumoxide compounds, zirconium oxide, zircon oxide, lanthanum oxide, orlanthanum oxide compounds; (strong) dielectric materials orsemiconductors; nitride ceramics such as silicon nitride, aluminumnitride, or titanium nitride; organic high-molecular materials such asacrylic resins, epoxy resins, polyamides, or polyimides; or alloys ofone or more metals selected from the group of Al, Li, Ti, Mn, In, Sn, Y,La, Ce, Nd, Pr, Gd, and Sm; by way of example. Materials are selected asappropriate therefrom to suit factors such as processing conditions andthe materials of the template 32 and the transparent electrode film 300.

[0251] The method of making the separation layer 304 is not particularlylimited, and can be selected as appropriate to suit the composition andthe film thickness thereof. More specifically, various vapor-phasemethods such as CVD, deposition, sputtering, or ion plating could beused therefor, or a method such as electro-plating, nonelectrolyticplating, a Langmuir blow-jet (LB) method, spin-coating, dipping,spray-coating, roll-coating, or bar-coating.

[0252] If the separation layer 304 is too thin, damage to thetransparent electrode film 300 will be greater; but if it is too thick,the amount of energy of the radiation 306 that must be applied to ensuregood separability of the separation layer 304 will have to be increased.To that end, the thickness of the separation layer 304 will differaccording to the separation objective and composition, but it ispreferably on the order of 1 nm to 20 μm, more preferably on the orderof 10 nm to 20 μm, and even more preferably on the order of 40 nm to 1μm. Note that the thickness of the separation layer 304 is preferably asuniform as possible.

[0253] If the radiation 306 is shone onto the thus-configured separationlayer 304 as shown in FIG. 26B, it can be separated from the template302. Different separation states are shown in FIGS. 27A to 27C.

[0254]FIG. 27A shows an example in which the bonding forces at theinterface between the template 302 and the separation layer 304 arereduced, so that separation occurs at that interface. In this case, itis preferable to wash the assembly, to remove the separation layer 304from the transparent electrode film 300.

[0255]FIG. 27B shows an example in which the bonding forces at theinterface between the transparent electrode film 300 and the separationlayer 304 are reduced, so that separation occurs at that interface. Inthis case too, it is preferable to wash the surface of the transparentelectrode film 300, because fragments of the separation layer 304 willadhere to the transparent electrode film 300.

[0256]FIG. 27C shows an example in which the bonding forces betweenmolecules or atoms are reduced within the separation layer 304, soseparation occurs there. In this case too, it is preferable to wash theassembly, to remove fragments of the separation layer 304 from thetransparent electrode film 300.

[0257] Note that the separation state is not limited to the abovedescribed three examples; it is also possible for combinations of theseseparations to occur locally.

[0258] A cross-sectional view through a thin-film transistor (TFT) colorliquid crystal panel that is combined with a color filter 210 is shownin FIG. 28. This color liquid crystal panel is provided with a glasssubstrate 204 a facing the color filter 210, with a liquid crystalcompound 202 a injected therebetween. The color filter 210 is providedwith red (R), green (G), and blue (B) colored layers 206 on a glasssubstrate 204 b to correspond to primary-color display elements of theliquid crystal panel, and is an essential filter for displaying colorsby the liquid crystal panel. An opaque layer (black matrix) 209 isformed between the colored layers 206, to improve the contrast andprevent mixing of the coloring materials. A protective layer 207 and acommon electrode 208 are formed in sequence on the colored layers 206.Transparent pixel electrodes 203 and TFTs (not shown in the figure) areformed on the matrix on the inner side of the glass substrate 204 a.Orientation films 201 a and 201 b are formed on the inner surfaces ofthe two glass substrates 204 a and 204 b, and the liquid crystalmolecules can be orientated in fixed directions by subjecting thosefilms to rubbing. Spacers 202 b for keeping the cell gap spacingconstant are inserted into the region (call gap) bounded by theorientation films 201 a and 201 b. Spheres of silica, polystyrene, orthe like are used as these spacers 202 b. A color display can beachieved by shining a backlight onto this liquid crystal panel andcausing the liquid crystal compound 202 a to function as an opticalshutter that varies the transmissivity of the backlight.

1. A method of making a color filter comprising: a first step offabricating a template having a plurality of protrusions in apredetermined array; a second step of transfer-forming an ink fillinglayer having a plurality of ink filling concavities by causing an inkfilling layer precursor to adhere to said template, solidifying said inkfilling layer precursor to form said ink filling layer, then separatingsaid ink filling layer from said template; and a third step of fillingsaid ink filling cavities with ink of previously determined colors, toform a color pattern layer.
 2. The method of making a color filter ofclaim 1 , wherein said first step comprises a step of forming a resistlayer of a predetermined pattern on a substrate, then forming saidprotrusions on said substrate by etching to obtain said template.
 3. Themethod of making a color filter of claim 2 , wherein: said substrate isa silicon wafer.
 4. The method of making a color filter of claim 1 ,wherein: said first step comprises a step of forming a resist layer of apredetermined pattern on a base plate, then making said base plate andsaid resist layer conductive, and further using electrodeposition todeposit metal by an electroplating method to form a metal layer, andfinally separating said metal layer from said base plate and said resistlayer to obtain said template.
 5. The method of making a color filter ofclaim 1 , wherein: said ink filling layer precursor used in said secondstep is a material which can be hardened by application of energy. 6.The method of making a color filter of claim 5 , wherein: said energy isat least one of light and heat.
 7. The method of making a color filterof claim 6 , wherein: said ink filling layer precursor is a resin whichis hardened by ultraviolet rays.
 8. The method of making a color filterof claim 1 , wherein: said ink is injected by an inkjet method in saidthird step.
 9. The method of making a color filter of any one of claims1 to 8 , wherein: an opaque material is injected into concavitiesbetween said protrusions of said template after said first step butbefore said second step, to form an opaque layer; and said opaque layeris integrated with said ink filling layer in said second step, by usingsaid template on which is formed said opaque layer.
 10. The method ofmaking a color filter of claim 9 , wherein: said opaque material isinjected by an inkjet method.
 11. The method of making a color filter ofclaim 9 , wherein: an inner side surface of each of said concavities ofsaid template is formed in a tapered shape in such a manner that area ofan aperture portion thereof is larger than area of a base surfacethereof.
 12. The method of making a color filter of claim 9 , wherein:each of said concavities of said template is formed in a tapered shapeat an aperture edge portion of an inner side surface thereof.
 13. Amethod of making a color filter, comprising: a first step of forming aplurality of colored layers; a second step of placing a protective filmprecursor on said colored layers; and a third step of forming aprotective film precursor layer by flattening a surface of saidprotective film precursor with a template having a flat surfacecorresponding to at least an optically transparent region of saidcolored layers, then hardening said protective film precursor layer toform a protective film.
 14. The method of making a color filter of claim13 , wherein: at least one concavity is provided in a surface of saidtemplate corresponding to a region other than an optically transparentregion of said colored layers; a shape of said concavities of saidtemplate is transferred to said protective film precursor layer in saidthird step, to form protrusions in said protective film corresponding tosaid concavities; and said protrusions act as support members formaintaining a constant spacing for injecting liquid crystal into aliquid crystal panel.
 15. The method of making a color filter of claim14 , wherein: said second step causes said concavities of said templateto be positioned above and between said colored layers.
 16. The methodof making a color filter of claim 14 , wherein: an inner shape of eachof said concavities is a circular cylindrical shape.
 17. The method ofmaking a color filter of claim 13 , wherein: said protective filmprecursor is a material which can be hardened by application of energy.18. The method of making a color filter of claim 17 , wherein: saidenergy is at least one of light and heat.
 19. The method of making acolor filter of claim 13 , wherein: said protective film precursor is aresin which is hardened by ultraviolet rays.
 20. The method of making acolor filter of any one of claims 13 to 19 , wherein: a transparentelectrode film is previously formed on said template; and after saidtransparent electrode film is placed in contact with said protectivefilm precursor, said protective film precursor layer is formed by saidtemplate, and said protective film precursor is hardened to form aprotective film in said third step, then said template is separated fromsaid protective film precursor layer, leaving said transparent electroderemaining on said protective film precursor layer.
 21. The method ofmaking a color filter of claim 20 , wherein: a separation layer isformed between said template and said transparent electrode film, topromote separation of said two components.
 22. A color filter comprisingan ink filling layer having a plurality of ink filling concavities; anda color pattern layer formed in said ink filling cavities, and whereinsaid ink filling layer is formed by causing a template having aplurality of protrusions in a predetermined array to adhere to an inkfilling layer precursor, then solidifying said ink filling layerprecursor.
 23. A color filter comprising a plurality of colored layers;and a protective film formed on said colored layers, and wherein saidprotective film is formed by flattening a surface of protective filmprecursor with a template having a flat surface corresponding to atleast an optically transparent region of said colored layers, thenhardening said protective film precursor layer.